Temperature Control Circuit Based on Thermoelectric Cooler

Abstract

The invention discloses a temperature control circuit based on a thermoelectric refrigerator. The control circuit comprises a TEC component, a thermistor, a TEC control unit, an MCU and a differential proportion circuit, wherein the thermistor is arranged on the surface of the TEC component and connected with the differential proportion circuit, the TEC control unit converts a TEC temperature adjusting signal from the MCU into a voltage signal for controlling the current flow direction, the TEC component absorbs heat or gives out heat according to the voltage signal from the TEC control unit, the differential proportion circuit performs differential amplification on the difference value between a collected thermistor voltage and a preset reference voltage, and a differential voltage is obtained. The MCU obtains sampling temperature of the current thermistor according to the differential voltage from the differential proportion circuit, and the TEC temperature adjusting signal is generated according to a comparison result between the sampling temperature of the thermistor and the preset target temperature. By applying the temperature control circuit based on the thermoelectric refrigerator, the cost of the temperature control circuit can be lowered, and the ADC use ratio can be improved.

Description

technical field [0001] The invention relates to the technical field of optical communication, in particular to a temperature control circuit based on a thermoelectric cooler. Background technique [0002] As people's demand for high bandwidth continues to increase, in the field of optical communication, the transmission rate of optical modules is required to be higher and higher, but the volume is getting smaller and smaller. The EML (Electro-absorption Modulated Laser) in the optical module has the characteristics of good spectral characteristics, fast response speed, and low power consumption, so it is widely used in optical communications. [0003] Since the central wavelength and output power of the EML laser are affected by the temperature of the laser, it is necessary to control the temperature of the EML laser to maintain the stability of the central wavelength and output power of the EML laser. Especially for DWDM (DenseWavelengthDivisionMultiplexing, dense lightwav...

AI Technical Summary

Problems solved by technology

Therefore, in the normal application environment, since the minimum resistance value of the thermistor is K-level, the minimum thermistor voltage sampled by the ADC will be much greater than 0V, that is, in the normal application environment, the thermistor voltage sampled by the ADC will be much higher than 0V. The resistance voltage range is only a part of the thermistor voltage range theoretically sampled by the ADC, so that the thermistor voltage range theoretically sampled by the ADC is not 100% utilized

In this way, due to the need to characterize the temperature corresponding to the conventional application environment with a smaller voltage range, the actual sampling accuracy of the ADC is reduced, resulting in poor stability of the laser temperature

[0006] In order to improve the stable accuracy of the laser temperature, it is often necessary to increase the number of analog-to-digital conversion bits of the ADC, which will increase the hardware design and production costs; at the same time, the stable accuracy of the laser temperature can be improved by increasing the number of analog-to-digital conversion bits of the ADC. , there is also a situation where the thermistor voltage range theoretically sampled by the ADC is not 100% utilized, making the utilization rate of the ADC lower

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